LED lighting apparatus having sterilizing function

ABSTRACT

A lighting apparatus is disclosed. The lighting apparatus according to one embodiment of the present disclosure includes: a white light emitting device including at least one first light emitting diode and a wavelength converter to implement white light; and at least one second light emitting diode emitting light suitable for producing a cell activating substance, wherein the first light emitting diode emits light having a central wavelength in a range of about 300 nm to about 420 nm, the second light emitting diode emits light having a central wavelength in a range of about 605 nm to about 935 nm, the wavelength converter includes a plurality of wavelength conversion substances to convert light of the first light emitting diode into white light, the lighting apparatus emits the white light implemented in the white light emitting device and light generated by the second light emitting diode to the outside, and, in irradiance spectrum of the white light implemented in the white light emitting device, irradiance of the central wavelength of light emitted from the first light emitting diode is smaller than that of a peak wavelength of blue light emitted from the wavelength conversion substance.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. patent application Ser. No.16/703,067, filed on Dec. 4, 2019, which claims priority to and thebenefit of U.S. Provisional Application No. 62/776,566, filed on Dec. 7,2018, each of which is hereby incorporated in its entirety by referencefor all purposes as set forth herein.

BACKGROUND Technical Field

Exemplary embodiments of the present disclosure relate to a lightingapparatus having a cell activating function.

As an inorganic light source, light emitting diodes have been used invarious fields including displays, vehicular lamps, general lighting,and the like. In particular, with various advantages such as longlifespan, low power consumption, and rapid response, light emittingdiodes have been replacing existing light sources in the art.

Meanwhile, sunlight exhibits a broad spectrum of wavelengths in theultraviolet, visible and infrared regions. The human body has survivedby adapting to sunlight, and in particular, cells in the human bodyabsorb light of wavelengths near the near infrared to use for cellactivity.

Meanwhile, it is well known that ultraviolet rays are generally harmfulto the human body, particularly the eyes or skin. In addition, somewavelength bands in the blue wavelength region may cause eye diseases orskin diseases.

SUMMARY

Exemplary embodiments of the present disclosure provide a lightingapparatus having a cell activating function without causing eyediseases, skin diseases and the like, and a lighting system having thesame.

Exemplary embodiments of the present disclosure provide a lightingapparatus capable of changing color temperature over time like sunlightand having a cell activating function and a lighting system having thesame.

Exemplary embodiments of the present disclosure provide a lightingapparatus capable of changing color temperature in consideration of thecolor temperature of sunlight according to a region and time and havinga cell activating function, and a lighting system having the same.

An exemplary embodiment of the present disclosure provides a lightemitting apparatus, including: a white light emitting device includingat least one first light emitting diode and a wavelength converter toimplement white light; and at least one second light emitting diodeemitting light suitable for producing a cell activating substance,wherein the first light emitting diode emits light having a centralwavelength in a range of about 300 nm to about 420 nm, the second lightemitting diode emits light having a central wavelength in a range ofabout 605 nm to about 935 nm, the wavelength converter includes aplurality of wavelength conversion substances to convert light of thefirst light emitting diode into white light, the lighting apparatusemits the white light implemented in the white light emitting device andlight generated by the second light emitting diode to the outside, and,in irradiance spectrum of the white light implemented in the white lightemitting device, irradiance of the central wavelength of light emittedfrom the first light emitting diode is smaller than that of a peakwavelength of blue light emitted from the wavelength conversionsubstance.

An exemplary embodiment of the present disclosure provides a lightemitting apparatus, including: a first light emitting unit including afirst first-light emitting diode emitting light having a centralwavelength in a range of about 300 nm to about 420 nm and a firstwavelength converter; a second light emitting unit including a firstsecond-light emitting diode emitting light having a central wavelengthin a range of about 300 nm to about 470 nm and a second wavelengthconverter; at least one second light emitting diode emitting lighthaving a central wavelength in a range of about 605 nm to about 935 nm,wherein the first light emitting unit emits light of a higher colortemperature than that of the second light emitting unit, the firstwavelength converter includes a blue wavelength conversion substance forconverting light emitted from the first first-light emitting diode intoblue light, and, in irradiance spectrum of light emitted to the outside,irradiance of the central wavelength of light generated by each lightemitting diode in the first and second light emitting units and emittedto the outside without wavelength conversion is smaller than that of apeak wavelength of wavelength-converted light emitted from the first andsecond wavelength converters.

In addition, embodiments of the present disclosure provide a lightingsystem including the lighting apparatus mentioned above.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the inventive concept, and are incorporated in andconstitute a part of this specification, illustrate exemplaryembodiments of the inventive concept, and, together with thedescription, serve to explain principles of the inventive concept.

FIG. 1 is a graph showing a degree of hazard according to wavelengths ofblue light.

FIG. 2 shows a spectrum of a white light source using a blue lightemitting diode according to a prior art.

FIG. 3 is a schematic plan view illustrating a lighting apparatusaccording to one embodiment of the present disclosure.

FIG. 4 is a schematic cross-sectional view taken along the line A-A ofFIG. 3 .

FIG. 5 shows representative spectra of a lighting apparatus according toone embodiment of the present disclosure.

FIG. 6 is a schematic cross-sectional view illustrating a lightingapparatus according to another embodiment of the present disclosure.

FIG. 7 is a schematic cross-sectional view illustrating a lightingapparatus according to another embodiment of the present disclosure.

FIG. 8 is a schematic cross-sectional view illustrating a lightingapparatus according to another embodiment of the present disclosure.

FIG. 9 is a schematic cross-sectional view illustrating a lightingapparatus according to another embodiment of the present disclosure.

FIG. 10 is a schematic cross-sectional view taken along the line B-B ofFIG. 9 .

FIG. 11 is a schematic cross-sectional view illustrating a lightemitting unit according to another embodiment of the present disclosure.

FIG. 12 is a block diagram illustrating a lighting apparatus accordingto an embodiment of the present disclosure.

FIG. 13 is a flowchart illustrating a method of driving a lightirradiation apparatus according to an embodiment of the presentdisclosure.

FIG. 14 is a flowchart illustrating a method of driving the lightirradiation apparatus according to an embodiment of the presentdisclosure.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings. Thefollowing embodiments are provided by way of example so as to fullyconvey the spirit of the present disclosure to those skilled in the artto which the present disclosure pertains. Accordingly, the presentdisclosure is not limited to the embodiments disclosed herein and canalso be implemented in different forms. In the drawings, widths,lengths, thicknesses, and the like of elements can be exaggerated forclarity and descriptive purposes. When an element or layer is referredto as being “disposed above” or “disposed on” another element or layer,it can be directly “disposed above” or “disposed on” the other elementor layer or intervening elements or layers can be present. Throughoutthe specification, like reference numerals denote like elements havingthe same or similar functions.

A lighting apparatus according to one embodiment of the presentdisclosure includes: a white light emitting device including at leastone first light emitting diode and a wavelength converter to implementwhite light; and at least one second light emitting diode emitting lightsuitable for producing a cell activating substance, wherein the firstlight emitting diode emits light having a central wavelength in a rangeof about 300 nm to about 420 nm, the second light emitting diode emitslight having a central wavelength in a range of about 605 nm to about935 nm, the wavelength converter includes a plurality of wavelengthconversion substances to convert light of the first light emitting diodeinto white light, the lighting apparatus emits the white lightimplemented in the white light emitting device and light generated bythe second light emitting diode to the outside, and, in irradiancespectrum of the white light implemented in the white light emittingdevice, irradiance of the central wavelength of light emitted from thefirst light emitting diode is smaller than that of a peak wavelength ofblue light emitted from the wavelength conversion substance.

The lighting apparatus having a cell activating function may be providedby using the second light emitting diode suitable for producing a cellactivating substance together with the white light emitting device.Since irradiance of light emitted from the first light emitting diode issmaller than that of the peak wavelength of blue light emitted from thewavelength conversion substance, the lighting apparatus may prevent thefirst light emitting diode from causing harm to the human body or fromcausing eye diseases or skin diseases.

The cell activating substance may be nitric oxide (NO) produced bycytochrome c oxidase activity in mitochondria. NO improves the health ofthe human body by affecting pain relief and improving blood circulation.

Further, light of the second light emitting diode absorbed by theintracellular mitochondria causes the mitochondria to produce more ATPsand enhance metabolism.

The second light emitting diode may emit light having a centralwavelength of about 605 nm to about 655 nm, about 685 nm to about 705nm, about 790 nm to about 840 nm, or about 875 nm to about 935 nm. Inthese wavelength ranges, an energy absorption rate of cytochrome coxidase is relatively higher. In particular, the cytochrome c oxidaseexhibits the highest absorption in the range of 790 nm to 840 nm, andfollowed by in the range of 875 nm to 935 nm. Accordingly, the secondlight emitting diode may include a light emitting diode having a centralwavelength at least in the range of 790 nm to 840 nm or in the range of875 nm to 935 nm.

In one embodiment, the wavelength converter may include wavelengthconversion substances for converting light of the first light emittingdiode into blue, green and red light. In another embodiment, thewavelength converter may include blue and orange wavelength conversionsubstances for converting light of the first light emitting diode intoblue and orange light.

The white light and light emitted from the second light emitting diodemay be mixed and emitted. For example, the lighting apparatus mayfurther include a diffusion plate for mixing the white light and lightemitted from the second light emitting diode.

Meanwhile, the wavelength converter may include a phosphor or a quantumdot. For example, the wavelength converter may include a blue phosphor,a green phosphor and a red phosphor. In embodiments, these phosphors maybe replaced individually or all with quantum dots.

In one embodiment, light emitted from the second light emitting diodemay be emitted to the outside without passing through the wavelengthconverter. In another embodiment, a portion of light emitted from thesecond light emitting diode may be wavelength-converted by thewavelength converter.

Meanwhile, the first light emitting diode may emit light having acentral wavelength in a range of about 400 nm to about 420 nm. Comparedwith a case of using ultraviolet rays, light having the wavelengthwithin this range may be used, thereby improving a light conversionefficiency.

Meanwhile, irradiance of light generated by the at least one secondlight emitting diode and emitted to the outside may be greater than thatof red light wavelength-converted by the wavelength converter andemitted. Accordingly, the cell activating substance may be producedusing the second light emitting diode.

The lighting apparatus may include a greater number of first lightemitting diodes than that of the at least one second light emittingdiode. Accordingly, the irradiance of the white light emitting device isgreater than that of the second light emitting diode.

Meanwhile, irradiance of light generated by the at least one secondlight emitting diode and emitted to the outside may be smaller than orequal to 570 W/m².

The lighting apparatus may further include a circuit board for mountingthe first light emitting diode and the second light emitting diode.

Meanwhile, the lighting apparatus may include a location informationreceiver for receiving location information; and a controller forreceiving the location information from the location informationreceiver and controlling a dose of light emitted from the white lightemitting device; wherein the controller may calculate a dose of light tobe emitted by the white light emitting device based on the locationinformation, and may control the white light emitting device to emitlight in an amount equivalent to the dose.

In an embodiment, the controller may calculate an appropriate dose basedon the location information provided by the location informationreceiver, and may control the light source to emit the appropriate dose.

In another embodiment, the location information receiver may calculatelocation information of the lighting apparatus, the controller mayreceive the location information and calculate a dose of external lightand an appropriate dose at the place where the lighting apparatus islocated, and may control the white light emitting device to emit lightin an amount equivalent to a difference between the appropriate dose andthe dose of external light.

In an embodiment, the controller may calculate time information from thelocation information and may control a dose of light to be emitted bythe white light emitting device according to the time information.

A lighting apparatus according to another embodiment of the presentdisclosure includes: a first light emitting unit including a firstfirst-light emitting diode emitting light having a central wavelength ina range of about 300 nm to about 420 nm and a first wavelengthconverter; a second light emitting unit including a first second-lightemitting diode emitting light having a central wavelength in a range ofabout 300 nm to about 470 nm and a second wavelength converter; at leastone second light emitting diode emitting light having a centralwavelength in a range of about 605 nm to about 935 nm, wherein the firstlight emitting unit emits light of a higher color temperature than thatof the second light emitting unit, the first wavelength converterincludes a blue wavelength conversion substance for converting lightemitted from the first first-light emitting diode into blue light, and,in irradiance spectrum of light emitted to the outside, irradiance ofthe central wavelength of light generated by each light emitting diodein the first and second light emitting units and emitted to the outsidewithout wavelength conversion is smaller than that of a peak wavelengthof wavelength-converted light emitted from the first and secondwavelength converters.

Since a plurality of light emitting units are included, a lightingapparatus capable of implementing white light having various colortemperatures may be provided. Accordingly, the lighting apparatus maychange the color temperature to suit the change of sunlight over time.In addition, intensity of blue light emitted from the light emittingdiodes of the lighting apparatus to the outside is made to be less thanthat of light wavelength-converted by the wavelength converter, and thusthe occurrence of eye diseases and skin diseases caused by the lightemitting diode may be prevented.

Moreover, the lighting apparatus may further include a third lightemitting unit including a first third-light emitting diode emittinglight having a central wavelength in a range of about 300 nm to about470 nm and a third wavelength converter, wherein the third lightemitting unit emits light of a higher color temperature than that of thesecond light emitting unit, and, in irradiance spectrum of light emittedto the outside, irradiance of the central wavelength of light generatedby the first third-light emitting diode in the third light emitting unitand emitted to the outside without wavelength conversion is smaller thanthat of a peak wavelength of wavelength-converted light emitted from thethird wavelength converter.

Meanwhile, the first to third wavelength converters may further includea green wavelength conversion substance for converting light emittedfrom the first light emitting diode into green light and a redwavelength conversion substance for converting light emitted from thefirst light emitting diode into red light, respectively. Accordingly,the first to third light emitting units may implement white light,respectively.

The first light emitting unit, the second light emitting unit and thethird light emitting unit may be driven independently of one another.

The first first- to first third-light emitting diodes may emit lighthaving a central wavelength in a range of about 400 nm to about 420 nm.The first first- to first third-light emitting diodes may emit lighthaving the same peak wavelength, but are not limited thereto.

Meanwhile, the cell activating substance may be nitric oxide (NO)produced by cytochrome c oxidase activity in mitochondria. Further,light of the second light emitting diode absorbed by the intracellularmitochondria causes the mitochondria to produce more ATPs and enhancemetabolism.

Furthermore, the second light emitting diode may emit light having acentral wavelength of about 605 nm to about 655 nm, about 685 nm toabout 705 nm, about 790 nm to about 840 nm, or about 875 nm to about 935nm. In these wavelength ranges, an energy absorption rate of thecytochrome c oxidase is relatively higher.

Light wavelength-converted by the wavelength converter and light emittedfrom the second light emitting diode may be mixed and emitted to theoutside. The mixed light may be white light.

Furthermore, the lighting apparatus may further include a diffusionplate suitable for mixing light wavelength-converted by the wavelengthconverter and light emitted from the second light emitting diode.

Meanwhile, the first first- to first third-light emitting diodes may bedisposed more than the at least one second light emitting diode,respectively.

The lighting apparatus may further include a circuit board on which thefirst first-to first third-light emitting diodes and the second lightemitting diode are mounted.

In an embodiment, the lighting apparatus may further include a locationinformation receiver for receiving location information, and acontroller for controlling a dose of light emitted from the first tothird light emitting units, wherein the controller may control the doseof light emitted from the first to third light emitting units based onthe location information.

In an embodiment, the controller may calculate an appropriate dose basedon the location information provided by the location informationreceiver, and may control the first to third light emitting units toemit the appropriate dose.

In an embodiment, the location information receiver may calculatelocation information of the lighting apparatus, the controller mayreceive the location information and calculate a dose of external lightand an appropriate dose at the place where the lighting apparatus islocated, and may control the first to third light emitting units to emitlight in an amount equivalent to a difference between the appropriatedose and the dose of external light.

In an embodiment, the controller may calculate time information from thelocation information and may control a dose of the light according tothe time information.

A lighting system according to other embodiments of the presentdisclosure includes a lighting apparatus installed indoors, wherein thelighting apparatus is one of the lighting apparatuses described above.

Hereinafter, embodiments of the present disclosure will be described indetail with reference to the accompanying drawings.

FIG. 1 is a graph showing a degree of hazard according to wavelengths ofblue light.

Blue light is known to cause eye diseases and skin diseases. Inparticular, blue light exhibits the highest degree of hazard between 430nm and 440 nm. A wavelength range of 420 nm to 455 nm exhibits 90% ormore degree of hazard based on the highest hazard value, that of 413 nmto 465 nm exhibits 70% or more degree of hazard, and that of 411 nm to476 nm exhibits 50% or more degree of hazard.

Meanwhile, ultraviolet rays harm the human body and exhibit the highestdegree of hazard, especially between 270 nm and 280 nm.

FIG. 2 shows a spectrum of a white light source using a blue lightemitting diode according to the conventional art.

Referring to FIG. 2 , the white light source according to theconventional art implements white light using a yellow phosphor, or agreen phosphor and a red phosphor together with a blue light emittingdiode. A type of phosphor and an amount of phosphor are controlledaccording to a color temperature, and an intensity of the blue lightincreases as the color temperature increases.

A blue light emitting diode used in the conventional white light sourcegenerally has a central wavelength (peak wavelength) in a range of 430nm to 470 nm. Blue light in this range has a relatively high degree ofhazard as shown in FIG. 1 . Therefore, as the color temperature of thewhite light source increases, the intensity of the blue light increases,thereby increasing the hazard of causing eye diseases or skin diseases.

FIG. 3 is a schematic plan view illustrating a lighting apparatusaccording to one embodiment of the present disclosure, and FIG. 4 is aschematic cross-sectional view taken along the line A-A of FIG. 3 .

Referring to FIG. 3 and FIG. 4 , the lighting apparatus may include acircuit board 11, a first light emitting diode 21, a wavelengthconverter 23 and a second light emitting diode 31.

The circuit board 11 may have a circuit pattern for supplying power tothe first and second light emitting diodes 21 and 31. The circuit board11 may be a printed circuit board, for example, a metal-PCB.

At least one first light emitting diode 21 is mounted on the circuitboard 11 as a light source for implementing the white light. A pluralityof first light emitting diodes 21 may be electrically connected to oneanother in various ways, for example, may be connected in series, inparallel or in series parallel.

The first light emitting diode 21 may have, for example, a centralwavelength in a range of about 300 nm to 420 nm, and may further have acentral wavelength in a range of 400 nm to 420 nm. In addition, sincethe first light emitting diode 21 has the central wavelength in thisrange, a substantial portion of light emitted from the first lightemitting diode 21 may be wavelength-converted by the wavelengthconverter 23. When the first light emitting diode 21 emits ultravioletrays, most of ultraviolet rays are wavelength-converted by thewavelength converter 23, thereby preventing ultraviolet rays from beingemitted to the outside. Furthermore, when the first light emitting diodehaving the central wavelength in the range of 400 nm to 420 nm is used,safety problems caused by ultraviolet rays may be eliminated in advance.

The wavelength converter 23 converts a wavelength of light emitted fromthe first light emitting diode 21. The wavelength converter 23 may be,for example, a molding member containing a phosphor or a quantum dot.The wavelength converter 23 covers the first light emitting diode 21.When the plurality of first light emitting diodes 21 are mounted on thecircuit board 11, the wavelength converter 23 may cover all of theplurality of first light emitting diodes 21.

The wavelength converter 23 includes a wavelength conversion substancefor implementing the white light together with light of the first lightemitting diode 21. In one embodiment, the wavelength converter 23 mayinclude a blue phosphor, a green phosphor and a red phosphor. In anotherembodiment, the wavelength converter 23 may include a blue phosphor andan orange phosphor. In another embodiment, the wavelength converter mayinclude a quantum dot.

Examples of the blue phosphor may include a BAM-based, aHalo-Phosphate-based or an aluminate-based phosphor, and may include,for example, BaMgAl₁₀O¹⁷:Mn²⁺, BaMgAl₁₂O₁₉:Mn²⁺ or (Sr,Ca,Ba)PO₄Cl:Eu²⁺.The blue phosphor may have, for example, a peak wavelength in a range of440 nm to 500 nm.

Examples of the green phosphor may include LuAG(Lu₃(Al,Gd)₅O₁₂:Ce³⁺),YAG(Y₃(Al,Gd)₅O₁₂:Ce³⁺), Ga-LuAG((Lu,Ga)₃(Al,Gd)₅O₁₂:Ce³⁺), Ga-YAG((Ga,Y)₃(Al,Gd)₅O₁₂:Ce³⁺), LuYAG ((Lu,Y)₃(Al,Gd)₅O₁₂:Ce³⁺),Ortho-Silicate ((Sr,Ba,Ca,Mg)₂SiO₄:Eu²⁺), Oxynitride((Ba,Sr,Ca)Si₂O₂N₂:Eu²⁺), or Thio Gallate (SrGa₂S₄:Eu²⁺). The greenphosphor may have a peak wavelength in a range of 500 nm to 600 nm.

Examples of the red phosphor may include a Nitride-based, aSulfide-based, a Fluoride or an Oxynitride-based phosphor, and,specifically, may include CASN(CaAlSiN₃:Eu²⁺), (Ba,Sr,Ca)₂Si₅N₈:Eu²⁺,(Ca,Sr)S₂:Eu²⁺), or (Sr,Ca)₂SiS₄:Eu²⁺. The red phosphor may have a peakwavelength in a range of 600 nm to 700 nm.

White light may be implemented by a combination of the first lightemitting diode 21 and the wavelength converter 23. FIG. 5 shows spectraof white light having various color temperatures implemented by thecombination of the first light emitting diode 21 and the wavelengthconverter 23.

As shown in FIG. 5 , white light of each color temperature isimplemented by the combination of light emitted from the first lightemitting diode and light emitted from the phosphors. In addition, it canbe confirmed that irradiance of light emitted from the first lightemitting diode 21 at all color temperatures is smaller than that oflight emitted from the blue phosphor. As the color temperatureincreases, although the irradiance of light emitted from the first lightemitting diode 21 also increases, the irradiance of blue light emittedfrom the blue phosphor increases even more. In addition, the irradianceof light emitted from the first light emitting diode may be smaller thanthat of light emitted from the green phosphor and may be smaller thanthat of light emitted from the red phosphor.

Accordingly, the lighting apparatus may prevent eye diseases or skindiseases from being caused by light emitted from the first lightemitting diode.

Referring back to FIG. 3 and FIG. 4 , the second light emitting diode 31may be spaced apart from the wavelength converter 23 to be mounted onthe circuit board 11. Light emitted from the second light emitting diode31 may be emitted to the outside without actually entering thewavelength converter 23. Accordingly, irradiance of light emitted fromthe second light emitting diode 31 may be improved.

The second light emitting diode 31 may be connected to the first lightemitting diode 21 in series or in parallel, or may be drivenindependently from the first light emitting diode 21.

Meanwhile, the second light emitting diode 31 emits light suitable forcell activation. The second light emitting diode 31 may emit lighthaving a central wavelength in a range of, for example, about 605 nm toabout 935 nm.

Red light or near infrared light in the range of about 605 nm to about935 nm produces a cell activating substance in the mitochondria.Specifically, the cytochrome c oxidase in the mitochondria absorbs lightin the range of about 605 nm to about 935 nm as a photoreceptor toincrease its activity, thereby producing NO. NO improves human health byaffecting pain relief and improving blood circulation. In addition, theactivity of the cytochrome c oxidase protein contributes to ATPproduction, and also affects cell damage treatment.

In particular, the second light emitting diode may emit light having acentral wavelength in a range of about 605 nm to about 655 nm, about 685nm to about 705 nm, about 790 nm to about 840 nm, or about 875 nm toabout 935 nm. In these wavelength ranges, an energy absorption rate ofcytochrome c oxidase is relatively higher. In particular, the cytochromec oxidase exhibits the highest absorption in the range of 790 nm to 840nm, followed by in the range of 875 nm to 935 nm, and then in the rangeof 605 nm to 655 nm.

The second light emitting diode 31 emitting light having the wavelengthof the relatively high energy absorption of the cytochrome c oxidase isincluded, and thus efficiency of health promotion may be improved.

Furthermore, when a plurality of second light emitting diodes 31 areused, it is possible to use the plurality of light emitting diodesemitting light in a specific wavelength range among the above wavelengthranges, for example, in the high efficiency range of 790 nm to 840 nm or875 nm to 935 nm, and various light emitting diodes may be used toevenly emit light in each of the wavelength ranges.

In addition, since the light emitting diode emitting light in the rangeof 605 nm to 655 nm may affect the color temperature of the white light,light emitting diodes emitting light having a central wavelength in alow visibility range, that is, in the range of about 685 nm to about 705nm, about 790 nm to about 840 nm, or about 875 nm to about 935 nm may bemainly used, not to affect the color temperature of the white lightemitting device.

In the present embodiment, to add the cell activating function to thelighting apparatus, the irradiance of light emitted from the secondlight emitting diode 31 is greater than that at the same wavelength oflight emitted from the white light emitting device. Furthermore, theirradiance of light emitted from the second light emitting diode 31 maybe greater than that of light emitted to the outside of the lightingapparatus from the first light emitting diode 21 having the centralwavelength in the range of 300 nm to 420 nm. Accordingly, the lightingapparatus of the present embodiment has the major cell activatingfunction provided by the second light emitting diode 31, compared to thefirst light emitting diode 21.

Meanwhile, although a driving time of the second light emitting diode 31and that of the first light emitting diode 21 may be the same, thepresent disclosure is not limited thereto, and the driving time of thesecond light emitting diode 31 may be adjusted according to aninstallation location of the lighting apparatus. In particular, a periodof use of the second light emitting diode 31 or a magnitude of theirradiance may be adjusted in consideration of the hazard to the humanbody.

For example, the irradiance of the second light emitting diode 31emitted from the lighting apparatus may be 570 W/m2 or less, andfurther, may be 100 W/m2 or less. 570 W/m2 represents a limit value ofrisk group 1 for light in the infrared range in the PhotobiologicalSafety Standard (IEC 62471), and 100 W/m2 corresponds to an exempt. Thelighting apparatus has the radiance of 570 W/m2 or less, and thus thelighting apparatus may be driven to produce a cell activating substancewithout harming the human body for a relatively long period of time.

In one embodiment, the lighting apparatus may include more the firstlight emitting diodes than the second light emitting diode, and thus mayemit light of intensity suitable for illumination. However, the presentdisclosure is not limited thereto.

According to the present embodiment, the lighting apparatus may be usedto promote the health of the human body not only in the indoor livingspace but also in a space where a large number of people are active suchas an airport or a hospital.

FIG. 6 is a schematic cross-sectional view illustrating a lightingapparatus according to another embodiment of the present disclosure.

Referring to FIG. 6 , the lighting apparatus according to the presentembodiment is generally similar to the lighting apparatus described withreference to FIG. 3 and FIG. 4 except that wavelength converters 23 areformed on the first light emitting diodes 21, respectively. That is, thewavelength converter 23 in FIG. 3 and FIG. 4 covers all of the pluralityof first light emitting diodes 21, but in this embodiment, each of thefirst light emitting diodes 21 is individually covered with thewavelength converter 23.

The wavelength conversion substances in the first light emitting diode21 and the wavelength converter 23 are the same as those describedabove, and thus a detailed description thereof will be omitted.

Meanwhile, since the first light emitting diodes 21 are respectivelycovered with the wavelength converters 23, the second light emittingdiode 31 may be disposed between the first light emitting diodes 21.That is, as shown in the drawing, the second light emitting diodes 31may be uniformly disposed between the first light emitting diodes 21,and thus light emitted from the second light emitting diode 31 may bemixed with the white light. As a result, the lighting apparatus of thepresent disclosure is capable of mitigating the external recognition oflight emitted from the second light emitting diode 31. The second lightemitting diodes 31 may be covered with a transparent molding member toprotect it from the external environment.

In the present embodiment, the second light emitting diodes 31 may beconnected in series or in parallel to the first light emitting diodes21, but the present disclosure is not limited thereto, and the secondlight emitting diodes 31 may be mounted on the circuit board 11 to bedriven independently from the first light emitting diodes 21.

FIG. 7 is a schematic cross-sectional view illustrating a lightingapparatus according to another embodiment of the present disclosure.

Referring to FIG. 7 , the lighting apparatus according to the presentembodiment is generally similar to the lighting apparatus described withreference to FIG. 3 and FIG. 4 except that the second light emittingdiode 31 is also covered with the wavelength converter 23.

That is, the wavelength converter 23 covers not only the first lightemitting diode 21 but also the second light emitting diode 31. Since thesecond light emitting diode 31 generally emits light having a longerwavelength than that of light emitted from the wavelength conversionsubstance in the wavelength converter 23, for example, a phosphor, lightemitted from the second light emitting diode 31 may be emitted to theoutside without being wavelength-converted by the wavelength converter23.

However, a portion of the light emitted from the second light emittingdiode 31 may be absorbed by the wavelength converter 23 and lost, andthus, more second light emitting diodes 31 than those in the previousembodiments may be used to implement the irradiance suitable for cellactivation. Meanwhile, light generated by the second light emittingdiode 31 may also be used to implement white light.

Meanwhile, the second light emitting diodes 31 may be uniformly disposedbetween the first light emitting diodes 21, and thus uniform light maybe emitted to the outside. However, the present disclosure is notnecessarily limited thereto.

Meanwhile, when the first light emitting diode 21 emits light having thecentral wavelength in the range of 300 nm to 420 nm, the number andintensity of the second light emitting diodes 31 are adjusted so thatthe irradiance of light generated by the second light emitting diodes 31and emitted to the outside without wavelength conversion is greater thanthat of light generated in the first light emitting diodes 21 andemitted to the outside without wavelength conversion.

Accordingly, the lighting apparatus according to the present embodimentalso provides an effective cell activating function by the second lightemitting diode 31.

FIG. 8 is a schematic cross-sectional view illustrating a lightingapparatus according to another embodiment of the present disclosure.

Referring to FIG. 8 , the lighting apparatus according to the presentembodiment is generally similar to the lighting apparatus described withreference to FIG. 3 and FIG. 4 except that it further includes adiffusion plate 51.

The diffusion plate 51 uniforms light by mixing the white light andlight emitted from the second light emitting diode 31. Accordingly,visibility of light emitted from the second light emitting diode 31 maybe reduced.

FIG. 9 is a schematic cross-sectional view illustrating a lightingapparatus according to another embodiment of the present disclosure, andFIG. 10 is a schematic cross-sectional view taken along the line B-B ofFIG. 9 .

Referring to FIG. 9 and FIG. 10 , the lighting apparatus according tothe present embodiment includes a substrate 11, a first light emittingunit 122, a second light emitting unit 124, a third light emitting unit126 and a second light emitting diode 31. Since the substrate 11 and thesecond light emitting diode 31 are similar to those described withreference to FIG. 3 and FIG. 4 , detailed descriptions thereof will beomitted to avoid redundancy.

Meanwhile, the first light emitting unit 122 includes a firstfirst-light emitting diode 121 a and a first wavelength converter 123 a,the second light emitting unit 124 includes a first second-lightemitting diode 121 b and a second wavelength converter 123 b, and thethird light emitting unit 126 includes a first third-light emittingdiode 121 c and a third wavelength converter 123 c.

In one embodiment, the first first- to first third-light emitting diodes121 a, 121 b, and 121 c may emit light having a central wavelength in arange of about 300 nm to about 420 nm, respectively. In particular, thefirst first- to first third-light emitting diodes 121 a, 121 b, and 121c may have a central wavelength in a range of about 400 nm to about 420nm. These may be the same light emitting diodes within these ranges, ormay be light emitting diodes having different central wavelengths.

Meanwhile, the first to third wavelength converters 123 a, 123 b, and123 c include a blue wavelength conversion substance for convertinglight emitted from the light emitting diode into blue light,respectively. The first to third wavelength converters 123 a, 123 b, and123 c may also include a green wavelength conversion substance forconverting light emitted from the light emitting diode into green lightand a red wavelength conversion substance for converting light emittedfrom the light emitting diode into red light, respectively. The blueconversion substance, the green wavelength conversion substance and thered wavelength conversion substance may be selected from the bluephosphor, the green phosphor and the red phosphor described withreference to FIG. 3 and FIG. 4 . These phosphors may also be replacedwith quantum dots.

Meanwhile, the first to third light emitting units 122, 124, and 126 mayemit white light having different color temperatures. For this purpose,the first to third wavelength converters may include differentwavelength conversion substances or different amounts of wavelengthconversion substances.

In addition, the first to third light emitting units 122, 124, and 126may be independently driven. For example, the first light emitting unit122 may implement white light having a color temperature of 6000K or6500K, the second light emitting unit 124 may implement white lighthaving a color temperature of 2700K, and the third light emitting unit126 may implement white light having a color temperature of 4000K. As aresult, the first to third light emitting units are selectively drivenfor a day, and thus the color temperature of the lighting apparatus maybe changed in accordance with the change of sunlight. In someembodiments, the first to third light emitting units 122, 124, and 126may be driven together, and may implement white light having a desiredcolor temperature together.

Meanwhile, in irradiance spectrum of light emitted to the outside,irradiance of the central wavelength of light generated by each of thelight emitting diodes 121 a, 121 b, and 121 c in the first to thirdlight emitting units 122, 124, and 126 and emitted to the outsidewithout wavelength conversion is smaller than that of a peak wavelengthof blue light emitted from the corresponding respective wavelengthconverters 123 a, 123 b, and 123 c. Accordingly, eye diseases or skindiseases may be prevented by the lighting apparatus.

The second light emitting diode 31 may be driven together when at leastone of the first to third light emitting units 122, 124, and 126 isdriven. In addition, the second light emitting diode 31 may be drivenindependently of the first to third light emitting units 122, 124, and126, and thus the second light emitting diode 31 may be driven even whenthe first to third light emitting units 122, 124, and 126 are notdriven. Therefore, the second light emitting diode 31 may operate toperform the cell activating function even at night when the lightingapparatus is not used.

Meanwhile, the first to third light emitting units 122, 124, and 126 maybe disposed so that each of the light emitting units is evenlydistributed. In the present embodiment, although the second lightemitting diodes 31 are shown to be disposed outside of locations wherethe first to third light emitting units 122, 124, and 126 are disposed,the present disclosure is not necessarily limited thereto, and may bedisposed together with the first to third light emitting units.

Moreover, in this embodiment, the first first- to first third-lightemitting diodes may be disposed more than the second light emittingdiodes in the lighting apparatus, respectively. However, the presentdisclosure is not necessarily limited thereto.

In the present embodiment, the first to third light emitting units 122,124, and 126 have structures where the wavelength converters 123 a, 123b, and 123 c surround the light emitting diodes 121 a, 121 b, and 121 c.For example, these light emitting units may be chip scale packages.However, the present disclosure is not limited thereto, but the lightemitting units 122, 124, and 126 may be light emitting devices in theform of a conventional package.

In addition, in the present embodiment, it is described that the colortemperature is changed by using three kinds of light emitting units 122,124, and 126, but four or more kinds of light emitting units or twokinds of light emitting units may be used to implement various colortemperatures. For example, by adjusting intensities of the first lightemitting unit 122 and the second light emitting unit 124, light of anintermediate color temperature between the color temperatures of thefirst light emitting unit and the second light emitting unit may bevariously implemented, and, accordingly, the third light emitting unit126 may be omitted. Alternatively, it is possible to implement light ofvarious color temperatures by including more light emitting units anddriving them in turn.

Moreover, in the present embodiment, the first first- to firstthird-light emitting diodes 121 a, 121 b, and 121 c are all described ashaving the central wavelength in the range of 300 nm to 420 nm, but thepresent disclosure is not necessarily limited thereto. A light emittingunit having a low color temperature, for example, the second lightemitting unit 124 may include a blue light emitting diode and awavelength converter. Therefore, the first second-light emitting diode121 b may have a central wavelength in a range of 300 nm to 470 nm. Thelight emitting unit having the low color temperature may be used withoutcausing eye diseases or skin diseases because the intensity of bluelight emitted to the outside is weak even when the blue light emittingdiode is used as in the related art. The third light emitting unit 126representing the intermediate color temperature may also employ the bluelight emitting diode if the intensity of blue light emitted to theoutside is weak. However, since the first light emitting unit 122 has ahigh color temperature, it is necessary to employ a light emitting diodehaving a central wavelength of about 420 nm or less.

Meanwhile, when the second light emitting unit 124 or the third lightemitting unit 126 employs the blue light emitting diode, they may use agreen phosphor and a red phosphor, or may use an orange phosphor,instead of using the blue phosphor.

FIG. 11 is a schematic cross-sectional view illustrating a lightemitting unit according to another embodiment of the present disclosure.Herein, FIG. 11 schematically shows a light emitting device in the formof a conventional package.

Referring to FIG. 11 , the first light emitting unit 122 includes afirst first-light emitting diode 121 a and a first wavelength converter123 a. The first first-light emitting diode 121 a may be mounted in acavity of a housing 120, and the first wavelength converter 123 a coversthe light emitting diode 121 a in the cavity. Meanwhile, the firstfirst-light emitting diode 121 a may be electrically connected to leadelectrodes through bonding wires.

The package of FIG. 11 is an example, and various kinds of packages maybe used. In addition, the first wavelength converter 123 a may cover thelight emitting diode 121 a in various shapes.

Meanwhile, although the first light emitting unit 122 isrepresentatively described here, the second light emitting unit 124 andthe third light emitting unit 126 may also be light emitting deviceshaving the same package form.

In addition, the second light emitting diode 31 may also be provided asa light emitting device in a package form and mounted on the substrate11. However, the second light emitting diode 31 may be covered with atransparent molding member instead of being covered with the wavelengthconverter.

Lighting apparatuses of the present disclosure may change the colortemperature of white light in response to the change in the colortemperature of sunlight over time. Furthermore, the lighting apparatusesof the present disclosure may change the color temperature of whitelight in consideration of the change in the color temperature ofsunlight according to a region.

FIG. 12 is a block diagram illustrating a lighting apparatus 100according to an embodiment of the present disclosure.

Referring to FIG. 12 , the lighting apparatus 100 according to anembodiment of the present disclosure includes a light source 30 emittinglight, a location information receiver for receiving locationinformation, and a controller 50 receiving the location information fromthe location information receiver and controlling a dose of lightemitted from the light source 30. Herein, the location informationrefers to information that can be obtained by using a global positioningsystem (GPS). Meanwhile, the light source 30 refers to a white lightsource that implements white light, and is an arbitrary light sourcecapable of changing the color temperature. For example, the light source30 may be the white light emitting device including the first lightemitting diode 21 and the wavelength converter 23 or the first to thirdlight emitting units 122, 124, and 126, but the light source 30 is notlimited thereto.

The location information receiver 40 receives the location informationfrom a satellite using GPS to calculate current location information ofthe lighting apparatus 100. That is, the location information mayinclude latitude and longitude, and the location information such ascurrent latitude and longitude of the lighting apparatus 100 may beobtained by location information received by the location informationreceiver 40. The location information obtained by using the locationinformation signal is provided to the controller 50.

The controller 50 calculates a dose of light to be emitted by the lightsource 30 based on the location information provided by the locationinformation receiver 40, and controls the light source 30 to emit lightas much as the dose of light. In other words, the controller 50 maycontrol whether the light is emitted or not, an amount of light, anintensity of light, an emission time, and the like. The controller 50may also control a dose of light to be emitted from the second lightemitting diode 31 to sterilize pathogenic microorganisms together withthe dose of the light source 30. In particular, the controller 50 maycontrol the dose of the light emitted from the second light emittingdiode 31 according to the dose of the white light source 30.

The power supplier 60 is electrically connected to the controller 50 tosupply power to the light source 30 and the location informationreceiver 40. In the drawing, the power supplier 60 is illustrated assuppling power to the light source 30 and the location informationreceiver 40 through the controller 50, but the present disclosure is notlimited thereto. The light source 30 and the location informationreceiver 40 may be directly connected to the power supplier 60,respectively.

The light source 30 and the location information receiver 40 may bedisposed on the substrate 11. However, the present disclosure is notlimited thereto, and the location information receiver 40 may bedisposed on a substrate different from the substrate 11 on which thelight source 30 is disposed.

Sunlight is not irradiated at the same intensity to all places on theearth. As the latitude becomes lower, the dose of sunlight becomeslarger, and, as the latitude becomes higher, the dose of sunlightbecomes smaller. In addition, the altitude becomes higher, the dose ofsunlight becomes larger, and, as the altitude becomes lower, the dose ofsunlight becomes smaller. Accordingly, depending on which country and inwhich place a user of the lighting apparatus 100 is present, the time ordegree of exposure to sunlight may vary.

In an embodiment of the present disclosure, a location of the lightingapparatus 100 is determined by using location information, a dose ofsunlight is calculated at the location, and then the visible lightcorresponding to the dose of sunlight is irradiated to a user, and thusthe user may obtain the effect of exposure to sunlight within a harmlesslimit to the human body.

This will be described with reference to the drawings.

FIG. 13 is a flowchart illustrating a method of driving a lightirradiation apparatus according to an embodiment of the presentdisclosure.

Referring to FIG. 13 , a location information receiver receives locationinformation: S11. For example, it may be determined that the lightirradiation apparatus is located in city B of country A according to thelocation information obtained from the location information receiver.

The received location information is provided to a controller, and thecontroller checks or calculates an appropriate dose of light to beemitted by the light irradiation apparatus based on the locationinformation: S13. For example, when city B of country A is determined,in addition to the latitude and longitude information of city B ofcountry A, information such as sunrise time, sunset time, and averageamount of sunshine may be calculated. When using the latitude andlongitude information, the sunrise and sunset time on the latitude andlongitude may be easily confirmed, and thus the controller may beconfigured to determine whether it is a day or night using an algorithmthat calculates the sunrise and sunset time on the current latitude andlongitude.

Using the information such as sunrise time, sunset time, and averageamount of sunshine, the controller may calculate the turn-on time,turn-off time, light intensity, etc. of the light source, so as to havea similar dose to that of the actual sunlight, that is, to have anappropriate dose. In particular, the controller may properly adjustwhether the light source is irradiated or not by accurately determiningthe day or night light without adding an illumination sensor.

The information such as sunrise time, sunset time, and average amount ofsunshine at each location may be stored in a separate memory in thecontroller, or may be easily obtained by accessing a separate internetnetwork or the like.

The controller is configured to irradiate light in a dose correspondingto the appropriate dose calculated by turning on or off the lightsource, to the user from the light source: S15. The user may beirradiated with the dose substantially the same as that of sunlight atthe place where he or she is, even if he or she does not go outdoors.

According to an embodiment of the present disclosure, even if the useris in an environment where he or she is hardly exposed to sunlight, forexample, living indoors for a long time, being in a hospital room or alimited space, or mainly being active at night, light similar tosunlight at the present location may be provided in an appropriate dosefor a suitable time. Accordingly, the user may be in a familiarenvironment, psychological stability of the user may be possible, andthe irradiation time may also be controlled by setting the sunrise orsunset time, thereby easily recovering the daily biorhythm.

In the embodiment described above, although it has been described that asingle light is used instead of sunlight based on the locationinformation, an embodiment of the present disclosure is not limitedthereto. The light irradiation apparatus may be used as a correctionlight source that compensates for a lack of external light in thepresence of natural light, ie, external light emitted from sunlight orlighting apparatuses. For example, in a place with high latitude, aamount of sunshine may be significantly lower than in a region with lowlatitude, in which case it is necessary to compensate for the lack ofsunshine. When the amount of sunshine is low, not only light in thevisible light wavelength band irradiated to the user may beinsufficient, but also light in the ultraviolet light wavelength bandmay be insufficient. In this case, the light irradiation apparatusaccording to the embodiment of the present disclosure may serve tocompensate for the insufficient light by additionally irradiating lightof the visible light wavelength band and light of the ultravioletwavelength band.

FIG. 14 is a flowchart illustrating a method of driving the lightirradiation apparatus according to an embodiment of the presentdisclosure.

Referring to FIG. 14 , a location information receiver receives locationinformation: S21. For example, it may be determined that the lightirradiation apparatus is located in city D of country C according to thelocation information obtained from the location information receiver.

The received location information is provided to a controller, and thecontroller calculates information such as sunrise time, sunset time, andaverage amount of sunshine at a current location based on the locationinformation, and, using the information such as sunrise time, sunsettime, and average amount of sunshine, calculates a current dose ofactual sunlight: S23.

Next, a difference between an appropriate dose required for the user andthe current dose is calculated: S25. For example, in the case of city Dof country C which is located in a region with high latitude and anamount of sunshine is insufficient, an amount of sunshine actuallyrequired is the appropriate dose, and a value obtained by subtractingthe current dose from the appropriate dose is an insufficient dose. Theappropriate dose required for the user may be stored in a separatememory or the like in the controller, or may be easily obtained byconnecting to a separate internet network or the like.

The controller is configured to irradiate light in a dose correspondingto the difference between the appropriate dose calculated by turning onor off the light source and the external light dose, that is, light withthe insufficient dose, to a target object from the light source: S27.

The user may be irradiated with the predetermined light in the dose mostappropriate to the user regardless of the place where he or she is. thatis most suitable for the user regardless of where he or she is.

Although various lighting apparatuses have been described above, thepresent disclosure is not limited to these specific embodiments. Inaddition, the lighting apparatus may be installed in not only an indoorliving space but also an indoor space used by a plurality of people,such as a hospital or an airport. Thus, a lighting system in which thelighting apparatus is installed may also be provided. This lightingsystem may be suitable for producing the cell activating substance, andmay operate the lighting apparatus to effectively produce the cellactivating substance even when people are inactive.

Although some exemplary embodiments have been described herein, itshould be understood that these embodiments are provided forillustration only and are not to be construed in any way as limiting thepresent disclosure. It should be understood that features or componentsof one exemplary embodiment may also be applied to other exemplaryembodiments without departing from the spirit and scope of the presentdisclosure.

What is claimed is:
 1. A lighting apparatus, comprising: a white lightemitting device including at least one first light emitting diode and awavelength converter to implement white light; and at least one secondlight emitting diode configured to emit light that causes a target toproduce a cell activating substance upon irradiation, wherein: the firstlight emitting diode is configured to emit light having a centralwavelength in a range of blue light; the second light emitting diode isconfigured to emit light having a central wavelength in a range of about605 nm to about 935 nm; the wavelength converter comprises a pluralityof wavelength conversion substances to convert light of the first lightemitting diode into white light; and the white light emitting device isconfigured to have, in irradiance spectrum of the white lightimplemented in the white light emitting device, an irradiance of lightemitted from the second light emitting diode to be greater than that oflight emitted from the white light emitting device at the samewavelength.
 2. The lighting apparatus of claim 1, wherein the cellactivating substance is nitric oxide (NO) produced by cytochrome coxidase activity in mitochondria.
 3. The lighting apparatus of claim 1,wherein the second light emitting diode is configured to emit lighthaving a central wavelength of about 605 nm to about 655 nm, about 685nm to about 705 nm, about 790 nm to about 840 nm, or about 875 nm toabout 935 nm.
 4. The lighting apparatus of claim 1, wherein thewavelength converter comprises a phosphor or a quantum dot.
 5. Thelighting apparatus of claim 4, wherein light emitted from the secondlight emitting diode is emitted to the outside of the lighting apparatuswithout passing through the wavelength converter.
 6. The lightingapparatus of claim 1, wherein an irradiance of light generated by the atleast one second light emitting diode and emitted to the outside of thelighting apparatus is greater than that of red lightwavelength-converted by the wavelength converter and emitted to theoutside of the lighting apparatus.
 7. The lighting apparatus of claim 6,wherein the lighting apparatus comprises a greater number of first lightemitting diodes than that of the at least one second light emittingdiode.
 8. The lighting apparatus of claim 6, wherein an irradiance oflight generated by the at least one second light emitting diode andemitted to the outside of the lighting apparatus is less than or equalto 570 W/m².
 9. The lighting apparatus of claim 1, further comprising acircuit board on which the first light emitting diode and the secondlight emitting diode are mounted.
 10. A lighting system comprising thelighting apparatus of claim 1 installed indoors.
 11. A lightingapparatus, comprising: a white light emitting device including at leastone first light emitting diode and a wavelength converter to implementwhite light; and at least one second light emitting diode configured toemit light that causes a target to produce a cell activating substanceupon irradiation, wherein: the first light emitting diode is configuredto emit light having a central wavelength in a range of blue light; thesecond light emitting diode is configured to emit light having a centralwavelength in a range of about 605 nm to about 935 nm; the wavelengthconverter comprises a plurality of wavelength conversion substances toconvert light of the first light emitting diode into white light; andthe white light emitting device is configured to have, in irradiancespectrum of the white light implemented in the white light emittingdevice, an irradiance of light generated by the second light emittingdiode and emitted to the outside of the lighting apparatus withoutwavelength conversion to be greater than that of light generated on thefirst light emitting diode and emitted to the outside of the lightingapparatus without wavelength conversion.
 12. The lighting apparatus ofclaim 11, further comprising a third light emitting diode configured toemit light having a central wavelength in a range of about 300 nm toabout 470 nm and a third wavelength converter, wherein: the third lightemitting diode is configured to emit light having a higher colortemperature than that of the second light emitting diode; and inirradiance spectrum of light emitted to the outside of the lightingapparatus, an irradiance at the central wavelength of light generated bythe third light emitting diode and emitted to the outside of thelighting apparatus without wavelength conversion is less than that at apeak wavelength of wavelength-converted light emitted from the thirdwavelength converter.
 13. The lighting apparatus of claim 12, whereineach of the first, second, and third wavelength converters furtherincludes a green wavelength conversion substance to convert lightemitted from the first light emitting diode into green light and a redwavelength conversion substance to convert light emitted from the firstlight emitting diode into red light.
 14. The lighting apparatus of claim12, wherein the first light emitting diode, the second light emittingdiode, and the third light emitting diode are configured to be drivenindependently from one another.
 15. The lighting apparatus of claim 12,wherein the first, second, and third light emitting diodes areconfigured to emit light having a central wavelength in a range of about400 nm to about 420 nm.
 16. The lighting apparatus of claim 11, wherein:the second light emitting diode is configured to emit light having acentral wavelength of about 605 nm to about 655 nm, about 685 nm toabout 705 nm, about 790 nm to about 840 nm, or about 875 nm to about 935nm; and the cell activating substance is nitric oxide (NO) produced bycytochrome c oxidase activity in mitochondria.
 17. The lightingapparatus of claim 11, wherein: light wavelength-converted by thewavelength converter and light emitted from the second light emittingdiode are configured to be mixed and emitted to the outside of thelighting apparatus; and the mixed light is white light.
 18. The lightingapparatus of claim 17, further comprising a diffusion plate configuredto mix light wavelength-converted by the wavelength converter and lightemitted from the second light emitting diode.
 19. The lighting apparatusof claim 11, wherein a number of the first light emitting diode disposedis greater than a number of the second light emitting diode.
 20. Thelighting apparatus of claim 11, further comprising a circuit board onwhich the first and second light emitting diodes are mounted.